需要make CSS(Javascript)这样下划线(来自codepen的一些例子)
@import url(http://fonts.googleapis.com/css?family=Quando);
*, *:after, *:before {
box-sizing: border-box;
-moz-box-sizing: border-box;
}
* {margin:0;padding:0;border:0 none;position: relative; outline: none;
}
html, body {
background: #004050;
font-family: Quando;
font-weight: 300;
width: 100%;
}
h2, h3 {
background: #0D757D;
width: 100%;
min-height: 200px;
line-height: 200px;
font-size: 3rem;
font-weight: normal;
text-align: center;
color: rgba(0,0,0,.4);
margin: 3rem auto 0;
}
.uno {background: #ff5e33;}
.dos.bis {background: #85144B;}
.dos {background: #FADD40;}
h3 {background: #2B5B89;}
h2 > a, h3 > a {
text-decoration: none;
color: rgba(0,0,0,.4);
z-index: 1;
}
h2 > a:before {
content: "";
position: absolute;
width: 100%;
height: 3px;
bottom: 0;
left: 0;
background: #9CF5A6;
visibility: hidden;
border-radius: 5px;
transform: scaleX(0);
transition: .25s linear;
}
h2 > a:hover:before,
h2 > a:focus:before {
visibility: visible;
transform: scaleX(1);
}
.uno a:before {
background: rgba(0,0,0,0);
box-shadow: 0 0 10px 2px #ffdb00;
}
.dos > a:after {
content: "";
position: absolute;
width: 100%;
height: 7px;
border: 1px solid #000;
bottom: -2px;
left: 0;
background: #fff;
border-radius: 5px;
opacity: 0;
transform: scalex(0);
transition: .5s;
}
.dos.bis > a:after {
opacity: .05;
transform: scalex(1);
}
.dos:hover > a:after {
opacity: .15;
transform: scalex(1);
}
.dos.bis > a:before {
background: rgba(0,0,0,0);
box-shadow: 0 0 10px 2px #FADD40;
}
.dos > a:before {
background: rgba(0,0,0,0);
box-shadow: 0 0 10px 2px #FF5E33;
}
h3 > a:before {
content: "";
background: #7FDBFF;
position: absolute;
width: 100%;
height: 5px;
bottom: 0;
left: 0;
border-radius: 5px;
transform: scaleX(0);
animation: 1.4s forwards no-hover-v linear;
animation-fill-mode: forwards;
z-index: -1;
}
h3 > a:hover:before,
h3 > a:focus:before {
animation: .5s forwards hover-v linear;
animation-fill-mode: forwards;
}
@keyframes hover-v {
0% {
transform: scaleX(0);
height: 5px;
}
45% {
transform: scaleX(1.05);
height: 5px;
}
55% {height: 5px;}
100% {
transform: scaleX(1.05);
height: 3.8rem;
}
}
@keyframes no-hover-v {
0% {
transform: scaleX(1.05);
height: 3.8rem;
}
45% {height: 5px;}
55% {
transform: scaleX(1.05);
height: 5px;
opacity: 1;
}
100% {
transform: scaleX(0);
height: 5px;
opacity: .02;
}
}
p {padding: .5rem;}
p a {color: rgba(255,255,255,.5)}
<h2>
<a href=''>:hover, please</a>
</h2>
但是下划线必须从左到右开始增长,然后以一定的速度从右到左减少。并且必须在没有鼠标悬停链接的情况下自动动画下划线。
当链接有鼠标悬停时,下划线必须同时增长到右边。
请编码如何执行此操作。
答案 0 :(得分:0)
使用node1
来控制transform-origin
的方向,您可以使用类来触发添加/删除边框。
scale()
var a = document.getElementById("a");
setTimeout(function() {
a.classList.add("under");
setTimeout(function() {
a.classList.remove("under");
}, 2000);
}, 500);
h2 {
background: #0D757D;
width: 100%;
min-height: 200px;
line-height: 200px;
font-size: 3rem;
font-weight: normal;
text-align: center;
color: rgba(0,0,0,.4);
margin: 3rem auto 0;
}
h2 > a {
text-decoration: none;
color: rgba(0,0,0,.4);
z-index: 1;
position: relative;
}
h2 > a:before {
content: "";
position: absolute;
width: 100%;
height: 3px;
bottom: 0;
left: 0;
background: #9CF5A6;
visibility: hidden;
border-radius: 5px;
transform: scaleX(0);
transition: .25s linear;
transform-origin: 0 0;
}
h2 > a.under:before {
visibility: visible;
transform: scaleX(1);
}